Spark-plug.



C. A. MBZGER.

SPARK PLUG.

APrLIoATIoN FILED Nov.2s,190a.

Patented N 1v. 14, 1911.

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UNITED STATES PATENT oi Flon ,CHARLES A. MEZGER, 0F NEW YORK, N. Y.

SPARK-PLUG.

Specification of Letters Patent.

Patented Nov. 14, 191'1.

To all whom"t ma/y concern:

Be it known that I, CHARLES A. Mnzenn, of the city of New York, borough of Brooklyn, State of New York, have invented certain new and useful Improvements in Spark-Plugs, of which the following is a full, clear, and exact specification, such as will enable others skilled Kin the art to which it ppertai'ns to make and use the same.

y invention relates to spark plugs for what is ordinarily termed the. jump spark or high tension system of electrical ignition or gasolene and other internal combustion engines and the object of my invention is to construct such a plug so that it will in its contained parts, as contradistinguished from at some otherv point in the circuit, embody an auxiliary 4gap through which the currentl must pass and by which the current is intensified.

A further object of the invention is to rotect t-he central electrode in event of the lireakage of the porcelain and consequent destruction of the insulation of said electrode. A

Still a further object is to provide a packing which will insure an absolutely pressure tight joint between the porcelain and the metal shell without, however, subject-ing such porcelain to destructive strains and by means of which the unavoidable expansion and contraction of the porcelain may take place without cracking.

.The invention involves various other features of importance and all will be fully set forth hereinafter and particularly pointed out in the claims. Y

-Reference is had to the accompanying drawings, which represent, as an example,

the referred embodiment of my invention,

`in w ich drawings,

Figure 1 is a longitudinal section of the plug; and Fi 2 is an enlarged section of the metal ban forming part'of the packing.

The body of the plug is formed of the usual shell a receiving in its outer end the gland b and having its inner end threaded as at a and rovided with a tercelain or equivalent insulation d an is formed -interiorly with a shoulder a2 between which and the inner end of the gland b. the enlargement d of the porcelain is received. The porcelain d is packed between its enlargement d -and the shoulder a' on one hand and the inner` end of the gland b on the other. This is efl'eci ed by two -gaskets c of asbestos or Vother so tt or fibrous material which are retained in place permanently bv a banddf of co] per or other soft metal. This lban is formed with an enlarged or thickened porti( n f at its `middle and with comparatively thin edge portions f2. The enlarged or thi :kened portion f engages the middle rtion of the enlarge-- ment al of t-he porce ain seating against the same between the gasket; e andthe thin edges f" embrace and c( ver said gaskets. After the gaskets and ban l are in place said thin edged portions f are crim ed or otherwise forced inward again it an around the This packing, therefore, `Jecomes a permanent part of the insulati )n d and may be freely removed from the `)lu with such insulation without dan r o E disaranging the packing. When the insu] ttion d is in position in the plug and the l gland b' is screwed home a directl positive prl assure is communicated from the gland t and shoulder a against the enlargement d of the porcelain or other insulation d and a hermetic joint is effected and against tl e. shoulder a2 and gland b by lthe proper o,- other soft metal edge portions f2 of the land f. This construction allows great pre ssure to be exerted by the gland without cai sing the gland of the shoulder of the shell a' to impinge di.

ment is a constant sour :e of breakage of invention relates. At t 1e same time the porcelain may be freely removed from the plug with the packing a; an integral part thereof and the construi tion and manipumore simple than with't 1e packing hereto fore employed.

The central electrode g of the plug is received-in the bore of the )orcelain d, but instead of being in direct contact therewith, there is interposed betv `een the porcelain and the electrode a sletve h of an insuelicient of expansion. S ich a material and that which I preferably employ is quartz which is fused and 1nold `d into the'form of a cylinder tube and-into which the centra electrode is cemented or otherwise secured. The quartz tube containing the electrode is then introduced and cem anted into the porcelain as shown in the d1 awing. 'Ihe result rectly against .the porcela in whichnirnpinge-l porcelain inplugs of the sort. to which my lating material with no or a minimum cogaskets snugly to engage 1 ynd hold the same.

lation of the plug thereby rendered far,

of this construction is that owing to the absence of a co-eficlent of ex lmnslon 1n the quartz and to its highly re ractory. nature it is not subject to the high temperature involved by the operation of the engine and, therefore, is not liable to breakage from contract-ion and expansion. The porcelain l furnishes a heavy mass of insulation which protects and reinforces the quartz or other tube k and said tube la. is in itself a suiicient insulation for the electrode. i

The insulation tube d terminates at and carries a cap i of brass or other metal which is fastened down over an enlargement on the upper end of the porcelain and which is adapted to be connected with the feed Wire in any desired manner, preferabl by what is known as a spark plug clip. he upper or outer end of the central electrode g terminates just short of the inner surface of this cap z' and in this manner a ap c is formed. Said gap is, therefore, Within the plug as an embodied part thereof and in this manner I increase in the intensity of the spark passed at the inner end of the plug without the disadvantage and diiliculty of a gap constructed in the wired portion of the circuit. The cap has no opening through its center'and serves the purpose not only of permitting connection of the positive wire with the plug, but also as a cover and protector for the upper end of the parts d, h and g.

Having t-hus described my invention, what I claim as new and desire to secure by Let- I ters Patent of the United States is:

1. A spark plug having an insulation mass with an enlargement, packing gaskets surrounding the lug at said enlargement and a soft metal and surrounding the enlargement and inclosing said gaskets to hold them upon the insulation mass.

2. A spark plug having an insulation mass with an enlar ement, acking gaskets surrounding the p ug at said enlargement and a soft4 metal band surrounding the enlargement and inclosing said gaskets, the edges of the band being rolled around said gaskets to hold them permanently and securely in place on the insulation mass.

3. A spark plug having an insulation mass with an enlargement, packing 'gaskets surrounding the lug at said enlargement and a soft metal and surrounding the enlargement and inclosing said skets, said band having an enlarged midd 'e portion lying between the' gaskets to stifen the band and space the gaskets. 4.

.spark plug having an insulation mass with an enlargement, packing gaskets surrounding the plug. at sald enlargement, and a soft 4metal and surrounding the env largement and inclosin band having an enlarg middle portion lying between the gaskets to stifen the band and space the gaskets and the thin edged portions of the band being rolled around the gaskets.

5. A spark plug having an insulation mass with an enlargement, a packing gasket encircling the mass at such enlargement and directly contacting therewith and a metal band surrounding the enlargement and encircling said gasket.

6. A spark plug having an insulation mass With. an enlargement, a shell in which the insulation mass is disposed and limiting the longitudinal movement of said )nass in one direction, a packing gasket surrounding. the mass at one end and a metal band surrounding the enlargement and encirclingl said gasket and having one end contracted to prevent longitudinal movement of said end past the enlargement.

7. A spark plug having a main insulation tube, a refractory insulation tube contained Withinthe main insulation and formed of said gaskets, said a material `having minimum co-etiicicnt of expansion, a cent-al elect-rode contained within said refractorgr insulation tube and terminating short of said second insulation tube and a metal cap mounted on the outerend of the main insulation and extending over the outer end of the central electrode out of act-ual electrical contact therewith.

'contracted below the lower gasket.

9. A spark plug having a shell presenting an annular shoulder, an, insulation mass disposed therein and presenting an annular enlargement adjacent to said shoulder, separate gaskets encircling said mass above and below the center of said enlargement, and a soft metal casing encircling sald gaskets and said enlargement and contracted above the uppergasket and contracted below the lower gasket. 4

In testimony whereof I have signed my name to this specification in the presence ofl two subscribing witnesses.

CHARLES A. MEZGER.

Witnesses:

,ISAAC B. OWENS,

RANDOLPH OWENS.. 

